There has been an increase in the demand for IP traffic and as a result a need for more bandwidth to support IP services. The number of IP-based applications and services are expected to continue increasing along with the number of wireless transmit/receive units (WTRUs). Therefore, system capacity becomes an issue when supporting a high number of WTRUs requiring high speed connections.
The current Evolved Packet Core (EPC) allows the use of non-3GPP access to connect to an operator Packet Data Network Gateway (PDN GW) via a node referred to as the Evolved Packet Data Gateway (ePDG). However, in this scheme the 3GPP and non-3GPP access networks are not tightly coupled. As a result, there is a need for new architecture and procedures to support non-3GPP offload, such as WiFi offload, with tighter 3GPP radio access networks (RAN) and non-3GPP access network coupling.